If you check out the BD website you'll find it states that they buy their vials from many different companies. I have products with very close manufacture dates and different size vials. As ultimate says, that's not a sign of a fake.

Ah ****, I have opened loads of enanthate and cyp like that before and not had a problem, will stop doing that though. It has a blue BD logo though and the bottle is taller. At least I got one shot out off it, will see how much it hurts tomorrow.